1. Field of the Invention
This invention pertains generally to buildings, and more particularly to enclosures including flexible fabric surfacing. A fastening structure for the flexible fabric surfacing is preferably formed from an extrusion having a fabric receiving channel. A fabric edged with a fastener may be inserted within the channel. The fastener is larger than the channel opening, to retain the fabric and fastener within the channel.
2. Description of the Related Art
In the construction of buildings, fabric may be used as a covering or barrier layer that may at least in part define a roof or sides of the building. This offers a lightweight alternative to other construction materials, can be moved readily in temporary structures, and allows more permanent structures to be expanded easily. For the purposes of the present disclosure, fabric materials will be understood to include woven and non-woven fabrics, films, and similar sheets. These materials may be fabricated from a single homogenous material, or from various laminates, including those of like or diverse compositions. Different fabrics may be used in part of or forming an entire building to regulate air, light, and moisture flow through the space. Fabric with a thicker, tubular edge typically called keder is often used in these situations, and the edges need to be secured to the structure in some way. These can be secured using keder rails.
A number of United States patents, the teachings and contents which are incorporated herein by reference, are exemplary of these keder structures: U.S. Pat. No. 1,991,358 by Bessy, entitled “Awning fixture”; U.S. Pat. No. 2,102,902 by Lenke, entitled “Skylight construction”; U.S. Pat. No. 2,189,567 by Miller, entitled “Awning strip”; U.S. Pat. No. 2,247,846 by Perlman, entitled “Hanging means for awnings and the like”; U.S. Pat. No. 2,287,667 by Brown, entitled “Awning fastener”; U.S. Pat. No. 2,950,727 by Dunn, entitled “Support for flexible awning covers”; U.S. Pat. No. 5,823,704 by Koch et al, entitled “Holding device for the anchorage of single- or multilayer webs to a stationary structural member”; U.S. Pat. No. 6,564,513 by Henbid et al, entitled “Extrusion design and fabric installation method for weather tight seal”; U.S. Pat. No. 7,127,851 by Morris, entitled “Building component”; U.S. Pat. No. 8,051,868 by Whitlow, entitled “Tent rafter end cap and tent incorporating same”; U.S. Pat. No. 8,056,602 by Green, entitled “Screen cover retainer strip assembly”; 2003/0163966 by Reynolds et al, entitled “Method and apparatus for cladding elongated structural members”; and 2004/0168383 by Reynolds et al, entitled “Method and apparatus for cladding elongated structural members”.
Many existing keder rails such as those listed herein above need to be attached into the structure's frame using a screw. While these aforementioned patents illustrate a variety of screws, a particularly popular screw currently in the trade is a TEK screw, explicitly illustrated in the aforementioned patent to Morris. Common TEK screws drill their own hole as they are being turned, and then they tap threads to couple the keder rail to the purlin, beam, frame or the like. As is known, TEK screws are relatively simple to install, only requiring a standard power drill. However, TEK screws can also easily strip a hole and are easily misaligned, particularly if they need removed and re-installed, making them more difficult to install and adjust than is desired. In addition, they are only capable of supporting a relatively limited load, in turn limiting the applications available for keder buildings. The hole formed by the TEK screw may form a weak point in the supporting structure, potentially leading to stress fractures or other adverse and weakening effects. Finally, the presence of any type of screw also means a hole exists that may initially or ultimately enable the intrusion of water and other potentially corrosive compositions into the building structure. The water or other corrosive agents can undesirably damage the building or the contents of the building. The present invention attempts to provide a more versatile keder rail attachment that preserves the moisture barrier where so desired.
Other patents illustrate bolting keder rails to structural members such as purlins, beams and the like. Exemplary US patents and published applications, the teachings and contents which are incorporated herein by reference, include: U.S. Pat. No. 3,173,224 by Aagaard, entitled “Roof structure”; U.S. Pat. No. 3,930,344 by Gahler, entitled “Plastic covered building structures”; U.S. Pat. No. 3,982,361 by Deutsch et al, entitled “Modified structure for lining generally curved surfaces”; U.S. Pat. No. 4,137,687 by Sprung, entitled “Stressed membrane space enclosure”; U.S. Pat. No. 6,158,181 by Musgrave et al, entitled “Roofing structures”; and 2010/0037544 by Musgrave et al, entitled “Covering apparatus”. Once again, these structures undesirably require holes for the bolts to pass through, creating conduits for damaging flow and weaker structure adjacent to the hole.
Other techniques are used to fasten keder rails. Exemplary US patents and published applications, the teachings and contents which are incorporated herein by reference, include: U.S. Pat. No. 3,875,623 by Johnston, entitled “Fabric joints”, which describes an unanchored bridging joint; U.S. Pat. No. 4,878,322 by Ikeda et al, entitled “Insulating plastic film structures and method”, which describes a strap anchor about a support tube; and U.S. Pat. No. 5,784,842 by Wackerbauer, entitled “Roof arrangement comprising tarpaulins and a plurality of lattice girders”, which describes a lattice girder having keder channels formed therein.
While somewhat less relevant hereto, the teachings and content of U.S. Pat. No. 4,321,780 by Hooper et al, entitled “Snap cap for architectural wall panel”, are additionally incorporated herein by reference.
In the prior art keder structures, tension in the fabric is generally created by inserting the keder into a keder rail that is already attached to a component of the structure's frame and then moving the component and rail together until the proper amount of tension is achieved. This limits the techniques available for attaching the structural components together, since they must be both adjustable in position and must be installed with the fabric in place. In one alternative, the teachings and content which are incorporated herein by reference, U.S. Pat. No. 5,333,425 by Nickerson et al, entitled “Tension membrane structure wrinkle elimination”, describes a multi-component structure that engages within a slot formed in the top of a support beam and allows the fabric to be tensioned after coupling to the support beam. Unfortunately, this Nickerson et al structure requires a plurality of extrusions where the prior art only required one, rendering the fabrication of the rail significantly more expensive. Additionally, a plurality of fasteners must be slid into position within the keder rail, requiring much additional time and thereby increasing the cost of installation. Nevertheless, the Nickerson et al invention offers much advantage over many of the prior art keder rails.
In addition to the foregoing patents, Webster's New Universal Unabridged Dictionary, Second Edition copyright 1983, is incorporated herein by reference in entirety for the definitions of words and terms used herein.